- In patients with HOCM, systolic septal bulging into the LVOT, malposition of the anterior papillary muscle, drag forces, and hyperdynamic LV contraction (causing a Venturi effect) may contribute to creation of a LVOT gradient.
- This type of obstruction is dynamic and is accentuated by any intervention that reduces ventricular size. Therefore, increases in contractility and heart rate or decreases in either preload or afterload are harmful because they facilitate septal-leaflet contact.
- Blood is ejected rapidly through this area and the anterior mitral valve leaflet is pulled even closer to the septum (systolic anterior motion).
- Treatment is multivariant depending on cause of HOCM
- β-blockers: DECR HR, SNS activity, oxygen requirement and dynamic outflow obstruction; prolongation of diastole
- Calcium Channel Blockers: improve ventricular filling and DECR ischemia
- Diuretics: must be done cautiously secondary to diastolic dysfunction
- Amiodarone: for paroxysmal A-FIB (DECR HR)